#!/usr/bin/env bash

# netdata
# real-time performance and health monitoring, done right!
# (C) 2017 Costa Tsaousis <costa@tsaousis.gr>
# GPL v3+
#
# charts.d.plugin allows easy development of BASH plugins
#
# if you need to run parallel charts.d processes, link this file to a different name
# in the same directory, with a .plugin suffix and netdata will start both of them,
# each will have a different config file and modules configuration directory.
#

export PATH="${PATH}:/sbin:/usr/sbin:/usr/local/bin:/usr/local/sbin"

PROGRAM_FILE="$0"
PROGRAM_NAME="$(basename $0)"
PROGRAM_NAME="${PROGRAM_NAME/.plugin}"
MODULE_NAME="main"

# -----------------------------------------------------------------------------
# create temp dir

debug=0
TMP_DIR=
chartsd_cleanup() {
    if [ ! -z "$TMP_DIR" -a -d "$TMP_DIR" ]
    then
        [ $debug -eq 1 ] && echo >&2 "$PROGRAM_NAME: cleaning up temporary directory $TMP_DIR ..."
        rm -rf "$TMP_DIR"
    fi
    exit 0
}
trap chartsd_cleanup EXIT
trap chartsd_cleanup SIGHUP
trap chartsd_cleanup INT

if [ $UID = "0" ]
then
    TMP_DIR="$( mktemp -d /var/run/netdata-${PROGRAM_NAME}-XXXXXXXXXX )"
else
    TMP_DIR="$( mktemp -d /tmp/.netdata-${PROGRAM_NAME}-XXXXXXXXXX )"
fi

logdate() {
    date "+%Y-%m-%d %H:%M:%S"
}

log() {
    local status="${1}"
    shift

    echo >&2 "$(logdate): ${PROGRAM_NAME}: ${status}: ${MODULE_NAME}: ${*}"

}

warning() {
    log WARNING "${@}"
}

error() {
    log ERROR "${@}"
}

info() {
    log INFO "${@}"
}

fatal() {
    log FATAL "${@}"
    echo "DISABLE"
    exit 1
}

debug() {
    [ $debug -eq 1 ] && log DEBUG "${@}"
}

# -----------------------------------------------------------------------------
# check a few commands

require_cmd() {
    local x=$(which "${1}" 2>/dev/null || command -v "${1}" 2>/dev/null)
    if [ -z "${x}" -o ! -x "${x}" ]
        then
        warning "command '${1}' is not found in ${PATH}."
        eval "${1^^}_CMD=\"\""
        return 1
    fi

    eval "${1^^}_CMD=\"${x}\""
    return 0
}

require_cmd date || exit 1
require_cmd sed || exit 1
require_cmd basename || exit 1
require_cmd dirname || exit 1
require_cmd cat || exit 1
require_cmd grep || exit 1
require_cmd egrep || exit 1
require_cmd mktemp || exit 1
require_cmd awk || exit 1
require_cmd timeout || exit 1
require_cmd curl || exit 1

# -----------------------------------------------------------------------------

[ $(( ${BASH_VERSINFO[0]} )) -lt 4 ] && fatal "BASH version 4 or later is required, but found version: ${BASH_VERSION}. Please upgrade."

info "started from '$PROGRAM_FILE' with options: $*"

# -----------------------------------------------------------------------------
# internal defaults
# netdata exposes a few environment variables for us

[ -z "${NETDATA_PLUGINS_DIR}" ] && NETDATA_PLUGINS_DIR="$(dirname "${0}")"
[ -z "${NETDATA_CONFIG_DIR}" ] && NETDATA_CONFIG_DIR="$(dirname "${0}")/../../../../etc/netdata"

pluginsd="${NETDATA_PLUGINS_DIR}"
confd="${NETDATA_CONFIG_DIR}"
chartsd="$pluginsd/../charts.d"

myconfig="$confd/$PROGRAM_NAME.conf"

minimum_update_frequency="${NETDATA_UPDATE_EVERY-1}"
update_every=${minimum_update_frequency}    # this will be overwritten by the command line

# work around for non BASH shells
charts_create="_create"
charts_update="_update"
charts_check="_check"
charts_undescore="_"

# when making iterations, charts.d can loop more frequently
# to prevent plugins missing iterations.
# this is a percentage relative to update_every to align its
# iterations.
# The minimum is 10%, the maximum 100%.
# So, if update_every is 1 second and time_divisor is 50,
# charts.d will iterate every 500ms.
# Charts will be called to collect data only if the time
# passed since the last time the collected data is equal or
# above their update_every.
time_divisor=50

# number of seconds to run without restart
# after this time, charts.d.plugin will exit
# netdata will restart it
restart_timeout=$((3600 * 4))

# check if the charts.d plugins are using global variables
# they should not.
# It does not currently support BASH v4 arrays, so it is
# disabled
dryrunner=0

# check for timeout command
check_for_timeout=1

# the default enable/disable value for all charts
enable_all_charts="yes"

# -----------------------------------------------------------------------------
# parse parameters

check=0
chart_only=
while [ ! -z "$1" ]
do
    if [ "$1" = "check" ]
    then
        check=1
        shift
        continue
    fi

    if [ "$1" = "debug" -o "$1" = "all" ]
    then
        debug=1
        shift
        continue
    fi

    if [ -f "$chartsd/$1.chart.sh" ]
    then
        debug=1
        chart_only="$( echo $1.chart.sh | sed "s/\.chart\.sh$//g" )"
        shift
        continue
    fi

    if [ -f "$chartsd/$1" ]
    then
        debug=1
        chart_only="$( echo $1 | sed "s/\.chart\.sh$//g" )"
        shift
        continue
    fi

    # number check
    n="$1"
    x=$(( n ))
    if [ "$x" = "$n" ]
    then
        shift
        update_every=$x
        [ $update_every -lt $minimum_update_frequency ] && update_every=$minimum_update_frequency
        continue
    fi

    fatal "Cannot understand parameter $1. Aborting."
done


# -----------------------------------------------------------------------------
# loop control

# default sleep function
LOOPSLEEPMS_HIGHRES=0
now_ms=
current_time_ms_default() {
    now_ms="$(date +'%s')000"
}
current_time_ms="current_time_ms_default"
current_time_ms_accuracy=1
mysleep="sleep"

# if found and included, this file overwrites loopsleepms()
# and current_time_ms() with a high resolution timer function
# for precise looping.
. "$pluginsd/loopsleepms.sh.inc"

# -----------------------------------------------------------------------------
# load my configuration

if [ -f "$myconfig" ]
    then
    . "$myconfig"
    [ $? -ne 0 ] && fatal "cannot load $myconfig"

    time_divisor=$((time_divisor))
    [ $time_divisor -lt 10 ] && time_divisor=10
    [ $time_divisor -gt 100 ] && time_divisor=100
else
    info "configuration file '$myconfig' not found. Using defaults."
fi

# we check for the timeout command, after we load our
# configuration, so that the user may overwrite the
# timeout command we use, providing a function that
# can emulate the timeout command we need:
# > timeout SECONDS command ...
if [ $check_for_timeout -eq 1 ]
    then
    require_cmd timeout || exit 1
fi

# -----------------------------------------------------------------------------
# internal checks

# netdata passes the requested update frequency as the first argument
update_every=$(( update_every + 1 - 1)) # makes sure it is a number
test $update_every -eq 0 && update_every=1 # if it is zero, make it 1

# check the charts.d directory
[ ! -d "$chartsd" ] && fatal "cannot find charts directory '$chartsd'"

# -----------------------------------------------------------------------------
# library functions

fixid() {
    echo "$*" |\
        tr -c "[A-Z][a-z][0-9]" "_" |\
        sed -e "s|^_\+||g" -e "s|_\+$||g" -e "s|_\+|_|g" |\
        tr "[A-Z]" "[a-z]"
}

run() {
    local ret pid="${BASHPID}" t

    if [ "z${1}" = "z-t" -a "${2}" != "0" ]
    then
        t="${2}"
        shift 2
        timeout ${t} "${@}" 2>"${TMP_DIR}/run.${pid}"
        ret=$?
    else
        "${@}" 2>"${TMP_DIR}/run.${pid}"
        ret=$?
    fi

    if [ ${ret} -ne 0 ]
    then
        {
            printf "$(logdate): ${PROGRAM_NAME}: ${status}: ${MODULE_NAME}: command '"
            printf "%q " "${@}"
            printf "' failed:\n --- BEGIN TRACE ---\n"
            cat "${TMP_DIR}/run.${pid}"
            printf " --- END TRACE ---\n"
        } >&2
    fi
    rm "${TMP_DIR}/run.${pid}"

    return ${ret}
}

# convert any floating point number
# to integer, give a multiplier
# the result is stored in ${FLOAT2INT_RESULT}
# so that no fork is necessary
# the multiplier must be a power of 10
float2int() {
    local f m="$2" a b l v=($1)
    f=${v[0]}

    # the length of the multiplier - 1
    l=$(( ${#m} - 1 ))

    # check if the number is in scientific notation
    if [[ ${f} =~ ^[[:space:]]*(-)?[0-9.]+(e|E)(\+|-)[0-9]+ ]]
        then
        # convert it to decimal
        # unfortunately, this fork cannot be avoided
        # if you know of a way to avoid it, please let me know
        f=$(printf "%0.${l}f" ${f})
    fi

    # split the floating point number
    # in integer (a) and decimal (b)
    a=${f/.*/}
    b=${f/*./}

    # if the integer part is missing
    # set it to zero
    [ -z "${a}" ] && a="0"

    # strip leading zeros from the integer part
    # base 10 convertion
    a=$((10#$a))

    # check the length of the decimal part
    # against the length of the multiplier
    if [ ${#b} -gt ${l} ]
        then
        # too many digits - take the most significant
        b=${b:0:${l}}

    elif [ ${#b} -lt ${l} ]
        then
        # too few digits - pad with zero on the right
        local z="00000000000000000000000" r=$((l - ${#b}))
        b="${b}${z:0:${r}}"
    fi

    # strip leading zeros from the decimal part
    # base 10 convertion
    b=$((10#$b))

    # store the result
    FLOAT2INT_RESULT=$(( (a * m) + b ))
}


# -----------------------------------------------------------------------------
# charts check functions

all_charts() {
    cd "$chartsd"
    [ $? -ne 0 ] && error "cannot cd to $chartsd" && return 1

    ls *.chart.sh | sed "s/\.chart\.sh$//g"
}

declare -A charts_enable_keyword=(
          ['apache']="force"
        ['cpu_apps']="force"
         ['cpufreq']="force"
         ['example']="force"
            ['exim']="force"
         ['hddtemp']="force"
    ['load_average']="force"
        ['mem_apps']="force"
           ['mysql']="force"
           ['nginx']="force"
          ['phpfpm']="force"
         ['postfix']="force"
         ['sensors']="force"
           ['squid']="force"
          ['tomcat']="force"
    )

all_enabled_charts() {
    local charts= enabled= required=

    # find all enabled charts

    for chart in $( all_charts )
    do
        MODULE_NAME="${chart}"

        eval "enabled=\$$chart"
        if [ -z "${enabled}" ]
            then
            enabled="${enable_all_charts}"
        fi

        required="${charts_enable_keyword[${chart}]}"
        [ -z "${required}" ] && required="yes"

        if [ ! "${enabled}" = "${required}" ]
        then
            info "is disabled. Add a line with $chart=$required in $myconfig to enable it (or remove the line that disables it)."
        else
            debug "is enabled for auto-detection."
            local charts="$charts $chart"
        fi
    done
    MODULE_NAME="main"

    local charts2=
    for chart in $charts
    do
        MODULE_NAME="${chart}"

        # check the enabled charts
        local check="$( cat "$chartsd/$chart.chart.sh" | sed "s/^ \+//g" | grep "^$chart$charts_check()" )"
        if [ -z "$check" ]
        then
            error "module '$chart' does not seem to have a $chart$charts_check() function. Disabling it."
            continue
        fi

        local create="$( cat "$chartsd/$chart.chart.sh" | sed "s/^ \+//g" | grep "^$chart$charts_create()" )"
        if [ -z "$create" ]
        then
            error "module '$chart' does not seem to have a $chart$charts_create() function. Disabling it."
            continue
        fi

        local update="$( cat "$chartsd/$chart.chart.sh" | sed "s/^ \+//g" | grep "^$chart$charts_update()" )"
        if [ -z "$update" ]
        then
            error "module '$chart' does not seem to have a $chart$charts_update() function. Disabling it."
            continue
        fi

        # check its config
        #if [ -f "$confd/$chart.conf" ]
        #then
        #   if [ ! -z "$( cat "$confd/$chart.conf" | sed "s/^ \+//g" | grep -v "^$" | grep -v "^#" | grep -v "^$chart$charts_undescore" )" ]
        #   then
        #       error "module's $chart config $confd/$chart.conf should only have lines starting with $chart$charts_undescore . Disabling it."
        #       continue
        #   fi
        #fi

        #if [ $dryrunner -eq 1 ]
        #   then
        #   "$pluginsd/charts.d.dryrun-helper.sh" "$chart" "$chartsd/$chart.chart.sh" "$confd/$chart.conf" >/dev/null
        #   if [ $? -ne 0 ]
        #   then
        #       error "module's $chart did not pass the dry run check. This means it uses global variables not starting with $chart. Disabling it."
        #       continue
        #   fi
        #fi

        local charts2="$charts2 $chart"
    done
    MODULE_NAME="main"

    echo $charts2
    debug "enabled charts: $charts2"
}

# -----------------------------------------------------------------------------
# load the charts

suffix_update_every="_update_every"
active_charts=
for chart in $( all_enabled_charts )
do
    MODULE_NAME="${chart}"

    debug "loading module: '$chartsd/$chart.chart.sh'"

    . "$chartsd/$chart.chart.sh"

    if [ -f "$confd/$PROGRAM_NAME/$chart.conf" ]
    then
        debug "loading module configuration: '$confd/$PROGRAM_NAME/$chart.conf'"
        . "$confd/$PROGRAM_NAME/$chart.conf"
    elif [ -f "$confd/$chart.conf" ]
    then
        debug "loading module configuration: '$confd/$chart.conf'"
        . "$confd/$chart.conf"
    else
        warning "configuration file '$confd/$PROGRAM_NAME/$chart.conf' not found. Using defaults."
    fi

    eval "dt=\$$chart$suffix_update_every"
    dt=$(( dt + 1 - 1 )) # make sure it is a number
    if [ $dt -lt $update_every ]
    then
        eval "$chart$suffix_update_every=$update_every"
    fi

    $chart$charts_check
    if [ $? -eq 0 ]
    then
        debug "module '$chart' activated"
        active_charts="$active_charts $chart"
    else
        error "module's '$chart' check() function reports failure."
    fi
done
MODULE_NAME="main"
debug "activated modules: $active_charts"


# -----------------------------------------------------------------------------
# check overwrites

# enable work time reporting
debug_time=
test $debug -eq 1 && debug_time=tellwork

# if we only need a specific chart, remove all the others
if [ ! -z "${chart_only}" ]
then
    debug "requested to run only for: '${chart_only}'"
    check_charts=
    for chart in $active_charts
    do
        if [ "$chart" = "$chart_only" ]
        then
            check_charts="$chart"
            break
        fi
    done
    active_charts="$check_charts"
fi
debug "activated charts: $active_charts"

# stop if we just need a pre-check
if [ $check -eq 1 ]
then
    info "CHECK RESULT"
    info "Will run the charts: $active_charts"
    exit 0
fi

# -----------------------------------------------------------------------------

cd "${TMP_DIR}" || exit 1

# -----------------------------------------------------------------------------
# create charts

run_charts=
for chart in $active_charts
do
    MODULE_NAME="${chart}"

    debug "calling '$chart$charts_create()'..."
    $chart$charts_create
    if [ $? -eq 0 ]
    then
        run_charts="$run_charts $chart"
        debug "'$chart' initialized."
    else
        error "module's '$chart' function '$chart$charts_create()' reports failure."
    fi
done
MODULE_NAME="main"
debug "run_charts='$run_charts'"


# -----------------------------------------------------------------------------
# update dimensions

[ -z "$run_charts" ] && fatal "No charts to collect data from."

declare -A charts_last_update=() charts_update_every=() charts_next_update=() charts_run_counter=() charts_serial_failures=()
global_update() {
    local exit_at \
        c=0 dt ret last_ms exec_start_ms exec_end_ms \
        chart now_charts=() next_charts=($run_charts) \
        next_ms x seconds millis

    # return the current time in ms in $now_ms
    ${current_time_ms}

    exit_at=$(( now_ms + (restart_timeout * 1000) ))

    for chart in $run_charts
    do
        eval "charts_update_every[$chart]=\$$chart$suffix_update_every"
        test -z "${charts_update_every[$chart]}" && charts_update_every[$charts]=$update_every
        charts_last_update[$chart]=$((now_ms - (now_ms % (charts_update_every[$chart] * 1000) ) ))
        charts_next_update[$chart]=$(( charts_last_update[$chart] + (charts_update_every[$chart] * 1000) ))
        charts_run_counter[$chart]=0
        charts_serial_failures[$chart]=0

        echo "CHART netdata.plugin_chartsd_$chart '' 'Execution time for $chart plugin' 'milliseconds / run' charts.d netdata.plugin_charts area 145000 ${charts_update_every[$chart]}"
        echo "DIMENSION run_time 'run time' absolute 1 1"
    done

    # the main loop
    while [ "${#next_charts[@]}" -gt 0 ]
    do
        c=$((c + 1))
        now_charts=("${next_charts[@]}")
        next_charts=()

        # return the current time in ms in $now_ms
        ${current_time_ms}

        for chart in "${now_charts[@]}"
        do
            MODULE_NAME="${chart}"

            if [ ${now_ms} -ge ${charts_next_update[$chart]} ]
            then
                last_ms=${charts_last_update[$chart]}
                dt=$(( (now_ms - last_ms) ))

                charts_last_update[$chart]=${now_ms}

                while [ ${charts_next_update[$chart]} -lt ${now_ms} ]
                do
                    charts_next_update[$chart]=$(( charts_next_update[$chart] + (charts_update_every[$chart] * 1000) ))
                done

                # the first call should not give a duration
                # so that netdata calibrates to current time
                dt=$(( dt * 1000 ))
                charts_run_counter[$chart]=$(( charts_run_counter[$chart] + 1 ))
                if [ ${charts_run_counter[$chart]} -eq 1 ]
                    then
                    dt=
                fi

                exec_start_ms=$now_ms
                $chart$charts_update $dt
                ret=$?

                # return the current time in ms in $now_ms
                ${current_time_ms}; exec_end_ms=$now_ms

                echo "BEGIN netdata.plugin_chartsd_$chart $dt"
                echo "SET run_time = $(( exec_end_ms - exec_start_ms ))"
                echo "END"

                if [ $ret -eq 0 ]
                then
                    charts_serial_failures[$chart]=0
                    next_charts+=($chart)
                else
                    charts_serial_failures[$chart]=$(( charts_serial_failures[$chart] + 1 ))

                    if [ ${charts_serial_failures[$chart]} -gt 10 ]
                        then
                        error "module's '$chart' update() function reported failure ${charts_serial_failures[$chart]} times. Disabling it."
                    else
                        error "module's '$chart' update() function reports failure. Will keep trying for a while."
                        next_charts+=($chart)
                    fi
                fi
            else
                next_charts+=($chart)
            fi
        done
        MODULE_NAME="${chart}"

        # wait the time you are required to
        next_ms=$((now_ms + (update_every * 1000 * 100) ))
        for x in "${charts_next_update[@]}"; do [ ${x} -lt ${next_ms} ] && next_ms=${x}; done
        next_ms=$((next_ms - now_ms))

        if [ ${LOOPSLEEPMS_HIGHRES} -eq 1 -a ${next_ms} -gt 0 ]
            then
            next_ms=$(( next_ms + current_time_ms_accuracy ))
            seconds=$(( next_ms / 1000 ))
            millis=$(( next_ms % 1000 ))
            if [ ${millis} -lt 10  ]
                then
                millis="00${millis}"
            elif [ ${millis} -lt 100 ]
                then
                millis="0${millis}"
            fi

            debug "sleeping for ${seconds}.${millis} seconds."
            ${mysleep} ${seconds}.${millis}
        else
            debug "sleeping for ${update_every} seconds."
            ${mysleep} $update_every
        fi

        test ${now_ms} -ge ${exit_at} && exit 0
    done

    fatal "nothing left to do, exiting..."
}

global_update
